Broiler oven with radiant gas burner



Dec. 17, 1963 s. M. KOLTUN 3,114,363

BROILER OVEN WITH RADIANT GAS BURNER Filed Sept. 10, 1959 6 Sheets-Sheet 1 INVENTOR SOLON M. KOLTUN ATTORNEYS Dec. 17, 1963 s. M. KOLTUN 3,114,363

BROILER OVEN WITH RADIANT GAS BURNER Filed Sept. 10, 1959 6 Sheets-Sheet 2 FIG. 5

INVENTOR SOLON M. KOLTUN BY l'emlurdduu ATTORNEYS Dec. 17, 1963 s. M. KOLTUN 3,114,363

BROILER OVEN WITH RADIANT GAS BURNER Filed Sept. 10', 1959 6 Sheets-Sheet 3 INVENTOR SOLON M. KOLTUN BY M M 4480 ATTORNEYS v Dec. 17, 1963 's. M. KOLTUN 3,114,363 7 BROILER OVEN WITH RADIANT GAS BURNER Filed Sept. 10, 1959 6 Sheets-Sheet 4 FIG. ll

I INVENTOR SOLON M. KOLTUN Dec. 17, 1963 s. M. KOLTUN 3,114,363

BROILER OVEN WITH RADIANT GAS BURNER Filed Sept. 10, 1959 6 Sheets-Sheet 5 INVENTOR SOLON M. KOLTUN ATTORNEYS av M, lam: 'M

Dec. 17, 1963 s. M. KOLTUN 3,114,353

BROILER OVEN WITH RADIANT GAS BURNER Filed Sept. 10, 1959 6 Sheets-Sheet 6 FIG. l6

INVENTOR SOLON M. KOLTUN ATTORNEYS United States Patent 3,114,363 BRUELER OVEN WETH RADIANT GAS BURNER Solon Michael Koltun, Cleveiand, Tenth, assignor to Hardwich Stove Qompany, leveland, Tenn, a corporation of Delaware Fiied Sept. 10, 1959, Ser. No. 839,098 15 Claims. (Cl. 1245-41) This invention relates, in general, to gaseous fuel burners, and has particular relation to an improved gaseous fuel burner for broiler ovens of gas ranges and the like, and to related aspects with regardto the burner and the burner and oven combination.

In general, broiling is accomplished in gas stoves, ranges and the like, in a compartment with overhead heat.

With prior structures, broiling has been relatively slow, considerable gaseous fuel and pre-heating have been required, and the broiling has not been as uniforn1,nor as satisfactory, as desired. Moreover, it has been diifioult to employ a conventional flame pilot burner because of the danger of the pilot flame being srmfied out by the ignition of the products of combustion emanating from the burner or by the opening and closing of the oven door or broiler door. Further, with prior burner structures it has been necessary to dependlargely on secondary air from the broiler or oven itself to sustain combustion.

Heretofore, due to the inability to provide proper distribution of heat in the broiler compartment, it has not been possible to use a thermostat to control the temperatures of this compartment, particularly the temperatures of a lower rotisserie and/ or roasting-baking oven section of such compartment. This has been due mostly to the inversion of heat above the object heated and controlled as in most prior broilers.

One of the main objects of the present invention is the provision of an improved gaseous fuel burner and broiler oven combination which overcomes the deficiencies and disadvantages of prior structures.

Another and more specific object is the provision of a burner surface with multiple port perforations having a swept wing face, or inclined burner face, for freeing or allowing the products of combustion emitting from the ports to be directed away from the radiant surface of the burner to reduce the interference to free emission of radiation by allowing the products of combustion to be swept off the radiant surface and/ or with the discharge of fuel from a related pilot burner, so that, in the latter case, the pilot burner will not be snuffed out.

Another object is the provision of baffle means positioned so as to convert the flow of the flowing gas-air mass from primarily kinetic to primarily potential energy, and more particularly for converting from velocity pressure within the mixing tube to static pressure Within the burner head. This is accombplished by the use of a filtering baffle screen.

Another object is the provision of improved mounting or supporting means for mounting and supporting the burner in overhead position within the broiler compar ment.

Further objects and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings, it being understood that the invention is limited only within the scope of the appended claims, and not to the particular embodiment selected for illustration.

In the drawings:

FEGURE 1 is a perspective view showing a conventional gas range having a broiler oven within which the burner embodying the present invention may be employed;

, FIGURE 2 is a fragmentary View looking upwardly into the broiler oven of FIGURE 1 and showing the burner mounted in overhead position therein;

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FIGURE 3 is a bottom plan view of the burner structure, partially broken away to show the inner details thereof;

FIGURE 4 is a fragmentary cross-sectional vie taken along the line #4 of FIGURE 3 and looking in the direction of the arrows, to show the means for supporting the ported ceramic or refractory member on the body of the burner;

FIGURE 5 is an end View of the burner illustrated in FXGURE 3 and showing the large throat and entrance area of the venturi mixing tube or passage and the ported burner members'disposed at an angle to one another;

FIGURE 6 is a view of the other end of the burner illustrated in FIGURE 3, showing the ported burner members at an angle to one another, and illustrating the area to be ignited by the pilot flame in the broiler oven;

FlG-URE 7 is a partial sectional View taken along the line 7"/' of FEGURE 6 and illustrating the head of the burner, the disposition of the pilot area ignited by the pilot flame, its communication with the head, and a portion of the mounting bracket;

FIGURE 8 is a cross-sectional view of the burner head illustrating the bafile means for converting from velocity pressure within the mixing tube to static pressure within the burner head; 1

FIGURE 9 is a semi-schematic enlarged sectional view of the pilot area, with the pilot burner located adjacent thereto to light the burner;

FEGURE 10 is a vertical sectional View illustrating the burner operatively arranged within the broiler oven;

FIGURE 11 is a fragmentary view showing the air.

chute and the gas nozzle adjustably located at the entrance to the venturi mixing tube;

FEGURE 12 is a cross-sectional view showing a vertical air chute arrangement with the gas nozzle located at the upper end thereof and at the entrance to the venturi mixing tube;

FIGURE 13 is a longitudinal sectional view through the venturi mixing tube illustrating the adjustability of the gas nozzle, the direction of circulation of the air from the air chute into the venturi tube and the effect that the positioning of the nozzle has on the flow of gas off true center;

FIGURE 14 is a horizontal sectional view through the venturi tube, as illustrated in FIGURE 13 and showing the flow of air into the venturi tube and the disposition of the battle means within the burner head;

FEGURE 15 is a schematic view showing piping connections for the burner as employed in the gas range of FIG- URE 1 with control means for operating the thermostat, the pilot, and for controlling the flow of gas into the burner head; and

FEGURE 16 is a fragmentary perspective view looloing into the broiler oven and showing the primary air inlet opening into the lower end of the vertical air chute shown in FIGURE 12.

Referring now to the drawings, the gas range it? illustrated in FIGURE 1 and fragmentaiily in FIGURES 2 and 10 has conventional top burners 11 and a bakeoven 12 provided with an oven door 13. Such a range is suitable for use, for example, in the home.

The improved gaseous fuel burner, designated in its entirety at 15, is disposed generally horizontally and mounted in overhead relation near the top or upper portion of the broiler-oven 16 which is disposed laterally of the bake oven 12. The interior of the broiler-oven compartment 16 is preferably formed of or lined at 1'7 with sheet aluminum, or other reflecting material which will reflect the radiant heat waves generated by the burner 15. As illustrated in FIGUE 10, the opposite side walls of the compartment 16 have one set of four racks 18 in the upper half of this compartment and another set of four racks 19 in the lower half of the compartment. These racks 13 and 19 are used for supporting trays and the like, and for supporting the outer edges of a conventional rotisserie indicated in its entirety at 2'9.

The lower section of the compartment 16 is used to prepare such slow broiling and cooking foods as roasts, chicken and generally bulky meats and foods requiring lower temperatures of broiler cooking. The upper section of the compartment 16 is used to prepare faster broiling and cooking meats and the foods requiring higher temperatures of broiler cooking.

A thermostatic capillary tube 21 is supported within the broiler-oven compartment 16 in horizontal position midway along the inner side of the right side wall and is subject to temperature control of the lower section of the compartment 16.

The floor 22 of the compartment 16 is provided with a plurality of large apertures 23 for the'circulation of air therefrom, and the broiler-oven 16 is provided with a door 24 which is preferably formed of or lined with sheet aluminum, or other suitablereflecting material for reflecting the radiant heat waves or rays generated by the burner 15.

As shown in FIGURES 3 through 9, the burner comprises a burner casing having a venturi mixing tube 25 at the outlet end of which is an enlargment, or head, defining an internal cavity or chamber 26 having an opening 27 directed downwardly and a relatively flat back or upper wall 23. As illustrated in FIGURES 2 and 10, the burner 15 is mounted near the ceiling or upper portion of the compartment 16 by an angle bracket 29 on the interior of the right side wall of this compartment, and by suspending the outer periphery of the entrance end of the venturi tube 25 in an inwardly extending flange 36 extending through an aperture 31 in the left side wall of the broiler-oven l6.

Marginally about the opening 27, the burner head has an outwardly extending flange 32 defining first and second angularly related ledge portions 33 and first and second retaining edges 34. First and second flat or planar burner plates 35 and 36 formed of ceramic or other suitable refractory material, are seated on the respective angular ledge portions 33 and within the respective retaining edges 34. The burner plates 35 and 36 are thus disposed angularly with respect to one another and meet centrally of the burner head at 37.

Each burner plate 35 and 36 has a plurality, or a large number of relatively small burner ports 38 and 39 respectively opening therethrough. The ports 38 are substantially normal to the generally parallel inner and outer surfaces of the plate or plates 35, and the ports 39 are substantially normal to the generally parallel inner and outer surfaces of the plate or plates 36. Thus, the products of combustion emitted through the ports 38 sweep away from the products of combustion emitted through the ports 39 and vice versa to reduce interference between the products of combustion along the radiant surfaces of the burner plates 35 and 36.

The burner plates 35 and 36 form ported closures for the opening 27 and radiant heat is generated along the outer Zones of the ports 38 and 39. The burner plates 35 and 36 and the ports or passages opening through these plates may, for example, be of the character more fully disclosed and claimed in United States Letters Patent No. 2,775,294 of Gunther Schwank, patented December 25, 1956. This ported ceramic material is sold under the trademark Schwank by Schwank Gasgerate G.m.b.H., Glucksburg, Germany, and is distributed in the United States through Perfection Industries, a division of Hupp Corporation of Cleveland, Ohio.

The burner casing is closed at the top by a top Wall and has depending side walls defining a generally rectangular chamber having a bottom opening 27 directed downwardly and covered by a porous burner surface of dihedral form over the outer areas of which radiant heat is generated.

Asbestos, or other suitable fire-proof or insulating spacing material 4% is interposed between the edges of the burner plates and 36, and the retaining edges 34. This material 4-0 prevents excess strain due to distortion of the burner surfaces of the plates 35 and 36, and provides a gaseous fuel seal against uncontrolled leakage at the outer margins of the burner plates.

A metal hold-down pressure plate, or plates, 41 are attached to the adjacent portion of the burner head, and more particularly to integral bosses 42 on the flange 32. As illustrated in FIGURE 4, the hold-down plate or member is generally Z-shaped in cross-section, and has flanges overlapping the margins of the burner plates 35 and 36 to hold these plates in place. The base flanges 44 of the members 41 are fastened, or secured to the bosses 42 by screws 45 which pass through apertures in the base flan es 44 and are screwed into threaded apertures 46 in the bosses 42.

The hold-down member 41 accommodates the thickness of the ceramic plates 35 and 36, which are slightly thicker than the depth of the ledges 33, and the member 41 is slightly larger than the outer periphery of the plates 35 and 36 to accommodate the expansion and contraction of the ceramic material due to the heat.

Air and gas entering the venturi 25 fills the cavity of the burner head and is forced out through the plurality of relatively small burner ports 38 and 39 in the ceramic plates 35 and 36. Since there are a large number of such ports, there is a large port area, and obviously a large volume of combustible gas-air mixture may be accommodated in the cavity in the burner head.

The large volume of the products of combustion which F requires a large entrance and a large throat area for the venturi mixing tube 25 to accommodate the large port area in the ceramic burner plates is an important feature of the present invention, and will be described in detail hereinafter. Suflice it to say here, however, that the venturi and burner head are so proportioned that optimum primary air and gas is used as the combustible material for the burner.

Baffle means 43 is positioned within the burner head cavity or chamber 26 generally across the fiow of gaseous fuel from the outlet portion of the mixing tube 25 for converting from velocity pressure within the tube 25 to static pressure within the chamber 26. Bailie means 48 is located near the exit 49 of the venturi tube 25 and the entrance to the cavity 26, and provides proper distribution of the gaseous fuel and conversion of the high velocity from the venturi to the static head in the cavity 26. This bafiie means 48 comprises, for example, a wire woven, or stamped-out, screen 51 and is located substantially to cover the exit 48 from the venturi. The screen or balfle means may be fastened to the wall 28 in any suitable manner, as, for example, by screw means 51, as illustrated in FIGURES 7 and 8. This screen of wire mesh permits the flow of gaseous fuel therethrough, and to the four corners of the burner cavity, as well as to a relatively small channel-shaped pilot extension 52 which opens into the cavity 26, and forms part thereof and part of the means for igniting the burner head, as will be described.

Pilot extension 52 comprises a three-walled cavity 53 as an extension of the burner cavity 26. The lower open side of the extension 52 is provided with a ported closure in the form of a small ceramic wall or plate 54 having ports 55 therethrough, similar to the burner plates 35 and 36. Hold-down members 56, similar to the holddown member 41, hold the ported plate 54 on the burner extension 52 against ledge 57, and within edge 58 in the manner in which the burner plates and 36 are held in place. Asbestos, or other fire-proof or insulating spacing material may be interposed between the edges of the plate 54 and the edge 58 in the manner and for the purposes previously described.

As illustrated in FIGURES 6, 7 and 9, the ported ceramic plate 54 is positioned to form a dihedral angle normal to the dihedral angle 37 formed between the burner plates 35 and 36 to direct the gaseous fuel emitted through the ports 55' toward the gaseous fuel outlet of pilot burner se. The pilot burner 61) is disposed at the angle where the burner plates 35 and 36 meet at 37, and with respect to the ported plate 54-, as illustrated in FEGURE 9. Thus, the products of combustion passing through the ports 38 and 39 of the burner plates 35 and 36 are swept away from the opposite sides of the pilot burner tit) to reduce interference with the pilot burner flame so that this flame will not be snuiled out or extinguished by the products of combustion passing through the burner plates 35 and 3-6.

Further to permit use of a pilot burner within the broiler-oven, without snufiing out of the pilot burner frame, shielding means is provided for the pilot burner flame. This shielding means compirses a spoon-shaped pilot shield 62 positioned under the fuel outlet or flame end of the pilot burner es, and in close proximity to the ported plate The shield as has an extension 63 suitably attached at 64 to the pilot burner. The shield 62 aids in stabilizing the pilot burner flame, and protects it from drafts, such as caused by opening and closing the broiler-oven door, or the like.

The burner 1% has triangular-shaped bracket arms 66 secured at 69 to the burner head, or formed integral with one end of the burner head, and provided with downwardly extending flange in near the apex of the triangle formed by the arms 66. In mounting the bur ner within the compartment 16, the flange 67 is inserted through a rectangular-shaped aperture 6% in the bracket 29. Thus, the burner 15 is supported within the broiler-oven 16 in an easily detachable or removable manner so that the burner may be conveniently removed and serviced as necessary or desired.

The pilot burner oil is supported, for example, on the interior of the right side wall of the broiler-oven 16 by a supporting bracket '76 attached to such wall, and connected to the pilot burner so by bolt and nut means 71.

The burner 15 radiates heat downwardly from the ported burner members, and a channel-shaped reflector 72 supported above the burner 15 and, for example, from the upper surface of the compartment 16, aids in refleeting the heat downwardly. The walls and top of the compartment 16 may be insulated by insulating means shown at '73.

As illustrated in FIGURES l1 and 12, a gas jet nozzle 75, connected to a suitable source of domestic gas by piping 76, is located with its gaseous fuel outlet directed into the entrance or orifice '77 of the venturi mixing tube 25. in FIG. 11 an air supply duct 7% is in open communication with the entrance or orifice 77 of the tube 25, and supplies air to the venturi tube 25 responsive to the flow of gas into the tube from the nozzle 75. The duct '73 may be located at the same level as the mixer tube or burner venturi and may provide for entry of primary air horizontally from the back of the range. The gas jet from the nozzle 75 causes the proper amounts of primary air from the duct 78 to enter the orifice F7 of the venturi tube 25, and to mix with the gas to provide a gas-air mixture which supports the described combustion on the surfaces of the burner members 35, 36 and 54.

in ETGURES 12 and 16 the primary duct is in the form of a chute or box-like enclosure Illlll which fits snugly to the side of the broiler-oven compartment or is disposed in the wall thereof. As shown in FIGURES l2 and 16, a primary air inlet 111 opens into the lower end of the chute ill at the floor level of the broiler compartm nt and the upper end of the chute 11% is in open communication with the burner mixer face or inlet '77 of the venturi mixing tube25.

The arrangement shown in FIGURES 12 and 16 takes its primary air supply at a level along the lower inside edge of the floor of the broiler compartment. Primary air is admitted through ports 193 (FIGURE 10) and then through ports 23 (FIGURES 1 and 10). The primary air is drawn into the lower end of the chute 119 through inlet 111 and pulled up through the chute 110 to the mixer level and through the mixer of the burner. Ventilation of the ignited or burned gases is accomplished by passiru upward above the burner through an exhaust opening 112; shown in FIGURE 10 and located in the rear vertical wall of the broiler compartment. Hot gases are exhausted by natural conventional draft action up a vertical duct or flue box to a slotted opening 113 located above the cooking level and in the background of the range as shown in FIGURE 1. FIGURE 1 also shows a similar slotted opening 114 for the bake oven 12.

The vertical arrangement for primary air, as shown in FIGURES l2 and 16, has certain important advantages: The stack action or chimney action created by virtue of heated stack increases the primary air supply by natural draft action and reduces the pull required by the burner orifice injection system and obtains maximum primary air to the burner. More stability is also obtained when the compartment door is either opened or closed. The pressure generated by sudden door closure is transmitted through the mixer head to the venturi side of the burner at the same time that the wave of air pres sure is directed at the port surface or burner face. The opposing pressure fronts cancel or neutralize one another and therefore reduce the disturbance of the flame at the surface of the burner. This pressure neutralization effect also appears to stabilize the pilot burner.

in order to accomplish the most efficient operation of the venturi mixing tube 25, an adjustable mounting bracket 32 (EEGURES 11 and 12) is provided for the gas nozzle 75. The bracket 82 comprises an elongated arm 83 which loosely cooperates with rectangular slot $4 in the Wall of air duct '78, or the wall of the air chute Till. The arm 83 has a centrally enlarged portion 85 which supports the nozzle 75. At the other end of the arm 83 are a pair of laterally extending arcuate arms 36 and 87. These arms as and 87 are apertured centrally thereof and provided, for example, with a wing nut assembly 83 which cooperates with an arcuate slot 99 in the adjacent wall of the duct 73 or chute 1161 to permit movement, or adjustment of the bracket 82 and nozzle '75, and to secure the same in the desired adjusted position.

Thus, the gas nozzle '75 is adjustably supported for adjustment so as adjustably to position the nozzle on the center line of the entrance or orifice '77 of the venturi tube 25, or otherwise to position the nozzle 75 for maximum venturiefficiency, and to obtain maximum primary air entrainment.

FIGURES 13 and 14 illustrate in full lines the position of the nozzle '75 with its axis coinciding with the axis of the venturi tube 25, and in dotted lines some of the various other positions to which the nozzle 75 may be adjusted. The vectors, or paths of air entrainment from the duct '73 and into the entrance '77 of the tube 25 are shown at 92.

The adjusting bracket 32 provides a simple and etficient means of individualizing the nozzle 75 with the venturi, and provides means for adjusting the nozzle for the most ideal venturi relationships so that the gas pressure from the nozzle will properly entrain sufficient air to give the proper mixture within the burner head for proper combustion regardless of the type and specific gravity of the domestic gas being used. For example,

if propane gas is used, having a higher specific gravity than other natural gases, it is conceivable that the nozzle '75 may be adjusted above the center line, as indicated at $5 in FIGURE 1 to provide for the proper entrance and mixture of the gas as it travels along the venturi.

On the other hand, if certain domestic gases are lighter than others, the nozzle '75 may have to be adjusted according to characteristics of the gas, such as specific gravity, pressure of operation, and volume of flow, and the adjusting bracket 82 provides a simple and efficient means for accomplishing such adjustment. Also, the nozzle '75 may with equal facility be adjusted within a geometric plane inscribed by the common displacement left to right and up and down. This universal adjustment of the nozzle will provide for ideal alignment, as shown at 96, in FIGURE 14.

The burner of the present application is essentially a 100 percent primary air burner, and generates about 1600 F. temperature at the ported ceramic burner surface, thereby producing infra-red radiant heat energy at three (3) micron wave length. This is known to be the most efiicient in terms of emissivity as measured in B.t.u.s per square foot micron for domestic broiiing and cooking by direct radiation. It has been difficult to achieve good primary air entrainment through a venturi when the maximum pressure of gas is only 4-inch equivalent water column, which is illustrative of domestic gas pressures at regular house levels. The present invention meets this problem.

By way of illustration of suitable dimensions of orificethroat-burner head relationship to support proper airgas entrainment, I have found that it the mixer face of the burner '77 is approximately three inches in diameter with the throat 93 approximately 1%; inches in diameter, sulficient primary air and gas mixture will be supplied to the burner head cavity 26 to support a port area of approximately to 12 square inches at a burner head pressure of .01 or less inch of water.

In one illustrative embodiment of the present invention, the area of the burner mixer face or inlet '77 of the venturi mixing tube is approximately 7.0686 square inches; the area of the throat 98 is approximately 0.9440 square inch; the volume of the burner head or burner cavity 26 is approximately 36.6 cubic inches; and the port area at the ports of the burner plates 35, .36 and 54 is approximately 13.46 square inches.

Variations in the aforementioned areas and the relation therebetween are contemplated within the scope of the present invention. For example, the entrance or inlet area of the venturi mixing tube may vary from approximately 5.94 square inches to approximately 9.62 square inches; the throat area may vary from approximately .69029 square inch to approximately 1.353 square inches; the burner head or burner cavity volume may vary from approximately 33.6 cubic inches to approximately 39.6 cubic inches; and the port area at the ports of the burner plates may vary from approximately 12.792 square inches to approximately 14.795 square inches.

In other words, with the foregoing dimensions of one illustrative embodiment of the burner, the ratio between the volume of the burner head and area of the throat is approximately 38.8 cubic inches of burner head volume per square inch of throat area; the ratio between the area of the mixer face and throat area is approximately 7.48; the ratio of port area to area of the mixer face is approximately 1.91; and the ratio between the burner volume and throat area may vary from approximately 29.3 cubic inches burner head volume per square inch of throat area to approximately 48.6 cubic inches burner head volume per square inch of throat area; whereas the ratio between the area of mixer face and the throat area may vary from approximately 7.12 square inches to approximately 8.6 square inches; and the ratio between the area of mixer face and area of throat may vary from approximately 1.54 to approximately 2.15.

The port loading of the burner head surface based on 13,000 B.t.u.s per hour rating is approximately 970 B.t.u.s per square inch of port area.

The use of the venturi and burner head structure of the present invention enables employment of low burner head tit 0 pressure, and provides approximately 10 cubic feet of air for every cubic foot of gas, to obtain a controlled reaction at a combustible temperature of approximately 1600 F., which is important for effective transfer of heat of three (3) micron wave lengths. The burner uses a large amount of primary air, i.e., that entrained responsive to the flow of gas from the nozzle 75, with a minimum of secondary air of less than 6%, as contrasted to conventional burners utilizing 40 to 60 percent of primary air which requires the venting of secondary air into the burner. At the same time I accomplish cooking at a rate to be described, utilizing only thirteen thousand (13,000) B.t.u.s per hour as compared to twenty-five thousand (25,000) to twenty-six thousand (26,000) B.t.u.s per hour in the conventional burner.

In the conventional burner, it is necessary to preheat the oven and then 15 to 20 minutes total time is required to cook meat, whereas with the burner of the present invention, utilized in a compartment such as shown and described herein, meat can be cooked in three (3) minutes without pre-heating the oven. Conventional burners are unable to charcoal broil a steak, and only stew the meat, whereas when using the burner according to the present invention, steaks can be charcoal broiled. In other words, only one-half the input of domestic gas is utilized to cook conventional cooked products in about one-half the time of conventional burners. Furthermore, the heat is distributed better throughout all positions of the rack, with a quality of evenness not heretofore obtained.

Since evenness of temperature is accomplished throughout the oven-broiler compartment, thermostatic control of the oven is made possible. So far as I am aware, I am the first to use a thermostatically controlled broiler in an oven-broiler compartment, and this is accomplished by the evenness of temperature which radiates from the burner 1'5.

As illustrated in FIGURE 15, the thermostatic capillary tube or bulb 21, shown in FIGURES 1 and 10, is connected to conventional valving means 100. Such capillary type temperature control may be, for example, of the type shown in United States Letters Patent to Weber et al., No. 2,303,011, issued November 24, 1942, and to E. Newell No. 2,307,636, issued January 5, 1943. The control illustrated in FIGURE 15 includes a shut-off control 102 under the control of the pilot flame at the pilot burner 60.

The burner of the present application is a new burner operated under new conditions. The relation of the volume of the head to the throat, for example, are entirely different from those normally expected in conventional Bunsen type burners. The fact that considerably more primary air is used than with conventional burners and yet the venturi dimensions are not expanded proportionwise, is a departure from the previously accepted theory. The application of the vertical chute for primary air supply in effect adds more venturi length by supplying air under pressure, as it were, which immediately brings in another factor with regard to the burner.

It is contemplated operating the burner of the present application with a high degree of primary air entrainment as well as radiant efiiciency at input rates from 9,000 B.t.u.s per hour to 15,000 B.t.u.s per hour. The 13,000 B.t.u.s per hour input, however, appears to be ideal.

The embodiment of the invention disclosed in the drawings and specification is for illustrative purposes only, and it is to be expressly understood that said drawings and the specification are not to be construed as a definition of the limits or scope of the invention, reference being had to the appended claims for that purpose.

I claim:

1. In combination, a broiler-oven compartment having top and side Walls and a floor having openings to the atmosphere for admission of atmospheric air, an overhead inverted burner in said broiler-oven compartment in proximity to said top wall and provided with air and fuel mixing means, a burner air supply chute having an air inlet opening into said compartment adjacent said floor and an outlet opening to said air and fuel mixing means, said burner air supply chute extending vertically within one of said side walls from adjacent said floor to position adjacent said top wall, and lining for an adjacent side wall forming the inner wall of said chute throughout substantially the vertical extent of said air supply chute through which the air supply to the burner through said chute is heated from said broiler-oven compartment.

2. In a gas range, a broiler-oven compartment having upright wall portions, a burner disposed in the upper portion of said broiler-oven compartment and having downwardly and outwardly directed generally planar ported burner portions disposed at an angle to one another with the tip of the angle directed downwardly and the generally planar ported burner portions inclined upwardly and outwardly from said tip at an obtuse angle to one another, a venturi mixing tube supported at its outer end on one of said upright wall portions, a burner casing at the outlet end of said mixing tube, said burner casing being of inverted dish-shaped form having a top wall and side walls defining a chamber opening downwardly to said ported burner portions over substantially the entire areas thereof to distribute a gas-air mixture evenly over the upper surfaces of said downwardly and outwardly directed ported burner portions, means for delivering into said burner casing through said ventun' mixing tube a gas-air mixture which supports combustion on the bottom surfaces of said downwardly and outwardly directed ported burner portions for emission of radiant-heat downwardly and outwardly from said burner portions, bracket means secured to said burner casing for supporting said burner casing on an opposite upright wall of said broiler compartment, the broiler-oven compartment having top and side walls and a floor having openings to the atmosphere for admission of atmospheric air, said burner being disposed in proximity to said top wall, a burner air supply chute having an air inlet opening into said compartment adjacent said floor and an outlet opening into the outer end of said venturi mixing tube, said burner air supply chute extending vertically within one of said side walls from adjacent said floor to position adjacent said top wall, and a lining for an adjacent side wall forming the inner side of said chute throughout substantially the entire vercal extent of said air supply chute through which the air supply to the burner through said chute is heated from said broiler-oven compartment.

3. In combination, an enclosed cooking chamber in which substances are cooked, said chamber having top and side walls and a floor, a burner including an overhead inverted burner casing in said chamber in proximity to said top wall and the top of said cooking chamber, a vertically elongated air chute extending vertically within one of said side walls from adjacent said floor to position adjacent to said top wall and the top of said cooking chamber, said air chute having a lower air inlet opening into said chute from said chamber near the bottom of said chamber and an upper air outlet opening from said chute near the top of said chamber, and an air and fuel mixing tube having an outer end connected to said air chute adjacent said upper air outlet opening for receiving air from said air chute through said upper air outlet opening and an inner end connected to deliver an air and fuel mixture into said burner casing. Y

4. The combination according to claim 3, wherein th air and fuel mixing tube comprises a venturi portion disposed wholly outside said burner casing and between said burner casing and the side wall in which said air chute is disposed.

5. The combination according to claim 3, wherein the burner casing has a bottom opening directed downwardly and covered by means forming a burner surface of dihedral form over the outer areas of which radiant heat 1G is generated, said burner surface having a multiplicity of outlets opening therethrough for discharging the air and fuel mixture from said burner casing.

6. The combination according to claim 3, wherein the burner casing has a bafile disposed in alignment with and transversely across the exit of the air and fuel mixing tube into the burner casing.

7; The combination according to claim 3, wherein the air and fuel mixing tube is supported at its outer end on the side wall in which the air chute is disposed and supports the burner casing at its inner end, and bracket means on said burner casing for supporting said burner casing on another side wall of said chamber.

8. The combination according to claim 3, wherein there is a gas nozzle discharging into the outer end of the air and fuel mixing tube. I

9. The combination according to claim 3, wherein the burner casing has a bottom opening directed downwardly and covered by means forming a burner surface of dihedral form over the outer areas of which radiant heat is generated, said burner surface having a multiplicity of outlets openin therethrough for discharging the air and fuel mixture from said burner casing, and a pilot burner located adjacent the edge of said burner surface.

10. The combination according to claim 3, wherein there is an annular flange adjacent the side wall in which the air chute is disposed and the outer end of the air and 'fuel mixing tube is supported in said annular flange.

11. The combination according to claim 3, wherein the air and fuel mixing tube comprises a venturi portion disposed wholly outside said burner casing and between said burner casing and the side wall in which said chute is disposed, the burner casing having a bottom opening directed downwardly and covered by means forming a burner surface of dihedral form over the outer areas of which radiant heat is generated, said burner surface having a multiplicity of outlets opening therethrough for discharging the air and fuel mixture from said burner casing, the burner casing having a bathe disposed in alignment with and transversely across the exit of the air and fuel mixing tube into the burner casing, and a pilot burner located adjacent the edge of said burner surface.

12. In combination, an enclosed cooking chamber in which substances are cooked, said chamber having top and side walls and a floor, an inverted overhead burner casing in said chamber with the top of the burner casing below but adjacent to the top wall of said chamber, an air chute extending vertically within one of said side walls from adjacent said floor to a position adjacent said top wall and the top of the cooking chamber, said air chute having a lower air inlet opening into said chute from said chamber adjacent the bottom of said chamber and an upper air outlet opening from said chute adjacent the top of said chamber, an air and fuel mixing tube having an outer end connected to said air chute adjacent said upper air outlet opening for receiving air from said air chute through said upper air outlet and an inner end connected to deliver an air and fuel mixture into said casing, the burner casing having a bottom opening directed downwardly and covered by means forming a burner surface of dihedral form over the outer areas of which radiant heat is generated, said burner surface hav-' ing a multiplicity of outlets opening therethrough for discharging the air and 'fuel mixture from said burner casing, the air and fuel mixing tube having a venturi portion disposed wholly outside said burner casing, a bafile disposed in alignment with and transversely across the exit of the air and fueltmixing tube into the burner casing, and a gas nozzle discharging into the outer end of the air and fuel mixing tube.

13. The combination according to claim 12, wherein there is a pilot burner located adjacent the edge of the porous burner surface of dihedral form.

14. The combination according to claim 12, wherein the burner surface of dihedral form is formed of ceramic material.

15. The combination according to claim 12, wherein there is a lining for an adjacent side Wall forming the inner side of said chute throughout substantially the entire vertical extent of said air supply chute through which the air supply to the burner through said chute is heated from said cooking chamber.

References Cited in the file of this patent UNITED STATES PATENTS Van Sept. 2, Lucke Mar. 12, Ellis May 27, Lucke Aug. 12, Maul Aug. 1 9, ODowd Apr. 19, Grohens June 11, Bibb Oct. 24, Lutenbacher Oct. 23,

Technologic Papers of the Bureau of Standards No.

OTHER REFERENCES Design of Atmospheric Gas Burners, Sept. 6, 1921. 

1. IN COMBINATION, A BROILER-OVEN COMPARTMENT HAVING TOP AND SIDE WALLS AND A FLOOR HAVING OPENINGS TO THE ATMOSPHERE FOR ADMISSION OF ATMOSPHERIC AIR, AN OVERHEAD INVERTED BURNER IN SAID BROILER-OVEN COMPARTMENT IN PROXIMITY TO SAID TOP WALL AND PROVIDED WITH AIR AND FUEL MIXING MEANS, A BURNER AIR SUPPLY CHUTE HAVING AN AIR INLET OPENING INTO SAID COMPARTMENT ADJACENT SAID FLOOR AND AN OUTLET OPENING TO SAID AIR AND FUEL MIXING MEANS, SAID BURNER AIR SUPPLY CHUTE EXTENDING VERTICALLY WITHIN ONE OF SAID SIDE WALLS FROM ADJACENT SAID FLOOR TO POSITION 